The present invention relates to an adsorption element for adsorbing vapors and/or gases from an air duct such as the air intake tract of an internal combustion engine.
An important development goal for modern internal combustion engines is a reduction of emissions. Increasing air pollution caused by the internal combustion engines of motor vehicles has led to the development of different testing and rating methods. These increased requirements are forcing automobile manufacturers, particularly in the American market, to minimize the hydrocarbons that leak from the engine's intake tract when a gasoline engine is shut off. It is expected that in the future the limits for these hydrocarbons will be further reduced and that the scope of application will be extended to an increasing number of countries. Thus, the automobile manufacturer is confronted with the problem of retaining the hydrocarbons that flow back when the engine is shut off. To achieve this, plate-like media, which are adapted to adsorb the hydrocarbons flowing past their surface, are disposed in the flow cross-section of the intake tract.
MPC of South Field, Mich. offers, for example, an adsorption element that can be integrated into a round flow cross section of an intake tract. To this end, a plate-shaped adsorption medium is wound parallel to the flow direction of the intake tract. The layers disposed in spiral form side by side are radially spaced apart and are stabilized along the end faces by support structures. A drawback in this embodiment is that the spiral arrangement makes the adsorption element mechanically very unstable so that support structures to impart sufficient rigidity are necessary. These support structures, which take up space in the flow cross section, add flow resistance and increase the cost of materials.